MODIS Image-derived ice surface temperature assessment in the Southern Patagonian Icefield

2019 ◽  
Vol 43 (6) ◽  
pp. 754-776
Author(s):  
A Lo Vecchio ◽  
E Lannutti ◽  
MG Lenzano ◽  
R Mikkan ◽  
P Vacaflor ◽  
...  
Keyword(s):  
Surface Temperature ◽  
River Flow ◽  
Correlation Coefficients ◽  
P Value ◽  
Santa Cruz ◽  
Ice Surface ◽  
Modis Image ◽  
Santa Cruz River ◽  
Influential Variable ◽  
Ice Surface Temperature

Ice surface temperature (IST) is one of the most relevant parameters when it comes to estimating the effects of climate change on glaciers. This study aims to estimate the IST for the Southern Patagonian Icefield (SPI) during the 2001–2016 period and, in so doing, to contribute to the assessment of the MOD11A1 product in this area. We evaluated IST performance by comparing it with that of automatic weather stations (AWSs). In addition, the glaciological significance of the results is presented through 1) IST trends, 2) annual IST anomalies, 3) IST behavior at different altitudes and orientations and 4) a comparison with Santa Cruz River flow records. The correlation coefficients obtained between the IST and AWSs ranged between 0.66 and 0.85. In addition, we report on the mean absolute differences between them, ranging between 0.6 ± 3.6°C and 9.4 ± 1.9°C. In this sense, we observed the lowest differences at the AWSs that were located in a homogeneous environment. Stated in glaciological terms: 1) only 1% of the pixels had a statically significant IST trend ( p-value ≤ 0.05): between 0.01 and 0.05°C/month; 2) we found that most of the IST anomalies ranged between –1 and 1°C throughout the period of this study; 3) the results suggest that the altimetric gradient was the most influential variable of the IST, mostly in north-oriented glaciers; and 4) the SPI IST showed an annual periodicity, which, in turn, shows a high correlation with the Santa Cruz River flow ( R = 0.86). This study is the first in estimating the SPI’s IST and contributes to enhance our knowledge of glacier dynamics and, therefore, the management of the water resource. Despite this, some MOD11 filtering is required in regions with high cloud cover frequency.

scholarly journals Melt probabilities and surface temperature trends on the Greenland ice sheet using a Gaussian mixture model

2021 ◽  
Author(s):  
Daniel Clarkson ◽  
Emma Eastoe ◽  
Amber Leeson
Keyword(s):  
Surface Temperature ◽  
Gaussian Mixture Model ◽  
Mixture Model ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Gaussian Mixture ◽  
Ice Surface ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Ice Surface Temperature ◽  
Model Components

Abstract. The Greenland ice sheet has experienced significant melt over the past six decades, with extreme melt events covering large areas of the ice sheet. Melt events are typically analysed using summary statistics, but the nature and characteristics of the events themselves are less frequently analysed. Our work examines melt events from a statistical perspective by modelling 19 years of Moderate Resolution Imaging Spectroradiometer (MODIS) ice surface temperature data using a Gaussian mixture model. We use a mixture model with separate model components for ice and meltwater temperatures at 1139 locations spaced across the ice sheet. By considering the uncertainty of the ice surface temperature measurements, we use the two categories of model components to define a probability of melt for a given observation rather than using a fixed melt threshold. This probability can then be used to estimate the expected number of melt events at a given location. Furthermore, the model can be used to estimate temperature quantiles at a given location, and analyse temperature and melt trends over time by fitting the model to subsets of time. Fitting the model to data from 2001–2009 and 2010–2019 shows increases in melt probability for significant portions of the ice sheet, as well as the yearly expected maximum temperatures.

scholarly journals Ice Surface Temperature Retrieval from a Single Satellite Imager Band

2018 ◽  
Vol 10 (12) ◽  
pp. 1909 ◽  
Author(s):  
Yinghui Liu ◽  
Richard Dworak ◽  
Jeffrey Key
Keyword(s):  
Surface Temperature ◽  
Infrared Imaging ◽  
Single Band ◽  
Dual Band ◽  
The Arctic ◽  
Landsat 8 ◽  
Ice Surface ◽  
Window Method ◽  
Comparable Performance ◽  
Ice Surface Temperature

Current methods for estimating the surface temperature of sea and lake ice—the ice surface temperature (IST)—utilize two satellite imager thermal bands (11 and 12 μm) at moderate spatial resolution. These “split-window” or dual-band methods have been shown to have low biases and uncertainties. A single-band algorithm would be useful for satellite imagers that have only the 11 μm band at high resolution, such as the Visible Infrared Imaging Radiometer Suite (VIIRS), or that do not have a fully functional 12 μm band, such as the Thermal Infrared Sensor onboard the Landsat 8. This study presents a method for single-band IST retrievals, and validation of the retrievals using IST measurements from an airborne infrared radiation pyrometer during the NASA IceBridge campaign in the Arctic. Results show that IST with a single thermal band from the VIIRS has comparable performance to IST with the VIIRS dual-band (split-window) method, with a bias of 0.22 K and root-mean-square error of 1.03 K.

Estimation of surface flow speed and ice surface temperature from optical satellite imagery at Viedma glacier, Argentina

2018 ◽  
Vol 169 ◽  
pp. 202-213 ◽  
Author(s):  
A. Lo Vecchio ◽  
M.G. Lenzano ◽  
M. Durand ◽  
E. Lannutti ◽  
R. Bruce ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Satellite Imagery ◽  
Flow Speed ◽  
Surface Flow ◽  
Ice Surface ◽  
Ice Surface Temperature

scholarly journals Arctic surface temperatures from Metop AVHRR compared to in situ ocean and land data

2012 ◽  
Vol 9 (2) ◽  
pp. 1009-1043 ◽  
Author(s):  
G. Dybkjær ◽  
R. Tonboe ◽  
J. Høyer
Keyword(s):  
Sea Ice ◽  
Surface Temperature ◽  
Temperature Data ◽  
Coupled Systems ◽  
The Arctic ◽  
In Situ Observation ◽  
Clear Sky ◽  
Ice Surface ◽  
Ice Surface Temperature

Abstract. The ice surface temperature (IST) is an important boundary condition for both atmospheric and ocean and sea ice models and for coupled systems. An operational ice surface temperature product using satellite Metop AVHRR infra-red data was developed for MyOcean. The IST can be mapped in clear sky regions using a split window algorithm specially tuned for sea ice. Clear sky conditions are prevailing during spring in the Arctic while persistent cloud cover limits data coverage during summer. The cloud covered regions are detected using the EUMETSAT cloud mask. The Metop IST compares to 2 m temperature at the Greenland ice cap Summit within STD error of 3.14 °C and to Arctic drifting buoy temperature data within STD error of 3.69 °C. A case study reveal that the in situ radiometer data versus satellite IST STD error can be much lower (0.73 °C) and that the different in situ measures complicates the validation. Differences and variability between Metop IST and in situ data are analysed and discussed. An inter-comparison of Metop IST, numerical weather prediction temperatures and in situ observation indicates large biases between the different quantities. Because of the scarcity of conventional surface temperature or surface air temperature data in the Arctic the satellite IST data with its relatively good coverage can potentially add valuable information to model analysis for the Arctic atmosphere.

scholarly journals AUTOMATED DEVICE FOR ICE SURFACE QUALITY ASSESSMENT

Doklady BGUIR ◽  
2020 ◽  
pp. 21-28
Author(s):  
M. V. Davydov ◽  
P. A. Belous
Keyword(s):  
Surface Temperature ◽  
Quality Assessment ◽  
Water Temperature ◽  
Surface Quality ◽  
Sliding Friction ◽  
Concrete Slab ◽  
Surface Hardness ◽  
Surface Friction ◽  
Ice Surface ◽  
Ice Surface Temperature

Results of ice quality assessment depending on various conditions of the environment and ice preparation are presented in article. The optimum indicators of the studied values influencing the ice surface quality are revealed. It is possible to estimate ice speed qualities objectively with the device, that imitates skater sliding. The purpose of the study is to determine the dependence of the sliding friction coefficient on the parameters of water treatment, the conditions for freezing the ice surface, the temperature of the ice surface, hardness and other parameters. The imitation is the movement of the mobile platform mounted on skates, supplied with the module transferring to the personal computer the values of skates sliding on the ice surface friction parameters. To measure the distance traveled by the device, the laser ranging method was used. The efficiency of the developed device and the technique of its application for assessment of ice quality on sports arenas are shown. The dependences of the quality of the ice surface on the surface temperature of the ice, air temperature, temperature of the poured water are considered. Accounting of these indicators during competitions allows to create «fast» ice for high sports results demonstration. The best values of the range of the device were recorded with the following parameters: ice surface temperature – from –3,5 to –4,5 °С, concrete slab temperature – –6 °С, ice thickness – 27–29 mm, filled water temperature – 50–55 °С, cutting the top layer of ice with an ice-filling machine – 100 %. The worst values of the range of the device were obtained with the following parameters: ice surface temperature – from –5,3 to –5,4 °С, filled water temperature – 30–35 °С, the top layer of ice was not cutby an ice-filling machine.

Experimental Investigation of the Tractive Performance of Pneumatic Tires on Ice

2020 ◽  
Vol 48 (1) ◽  
pp. 22-45 ◽  
Author(s):  
Emilio Jimenez ◽  
Corina Sandu
Keyword(s):  
Surface Temperature ◽  
Normal Load ◽  
Operating Conditions ◽  
Normal Operation ◽  
Inflation Pressure ◽  
Contact Patch ◽  
Ice Surface ◽  
Ice Surface Temperature ◽  
Drawbar Pull ◽  
Pneumatic Tires

ABSTRACT This investigation was motivated by the need for performance improvement of pneumatic tires in icy conditions. Under normal operation, the pneumatic tire is the only force-transmitting component between the terrain and the vehicle. Therefore, it is critical to grasp the understanding of the contact mechanics at the contact patch under various surfaces and operating conditions. This article aims to enhance the understanding of the tire-ice contact interaction through experimental studies of pneumatic tires traversing over smooth ice. An experimental design has been formulated that provides insight into the effect of operational parameters, specifically general tire tread type, slip ratio, normal load, inflation pressure, ice surface temperature, and traction performance. The temperature distribution in the contact patch is recorded using a novel method based on thermocouples embedded in the contact patch. The drawbar pull is also measured at different conditions of normal load, inflation pressure, and ice temperatures. The measurements were conducted using the Terramechanics Rig at the Advanced Vehicle Dynamics Laboratory. This indoor single-wheel equipment allows repeatable testing under well-controlled conditions. The data measured indicates that, with the appropriate tread design, the wheel is able to provide a higher drawbar pull on smooth ice. With an increase in ice surface temperature, a wet film is observed, which ultimately leads to a significant decrease in traction performance.

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